I really don't know what's missing. Most XBMC user seems to be careless for the one feature missing from XBMC. TV support. Well what about this proposal (that's why i'm posting a new thread).

1) Download & Install MP TV-Server (only TV-Server needed)
2) Configure XMLTV for the TV-Server (it has autoupdate and all)
3) Intall the PiipTV plugin for RTSP streaming
4) Install a (not writen) script on XBMC
- To get the EPG from the PiipTV's HTTP server
- The XML has RTSP Url's for each channel (rtsp://IP:8554/ptv_CHANNEL.sdp)
- Display the programming and have buttons for viewing the channels
- You can even pass parameters to have the channel name on display
5) Be happy and watch TV over the LAN

There is a real patch for TVServer support on trac aswell.
as soon as a developer starts using the mps tvserver it will get implemented. I myself will probably start use it in a few weeks or so. So the patch might get in to the next point release.